Plants Collected in the Percy Sladen Memorial Expeditions. 357 



neither with Namaqualand nor with Bushmanland, but with the Cape. 

 At the same time, it contains many forms whose affinities are with 

 the two former regions. Until this extensive range has been more 

 exhaustively explored, there appears good reason for raising it pro- 

 visionally to regional rank. This is done in the following pages under 

 the title of the " Khamiesberg region." 



The term Bushmanland, as used below, connotes merely that part 

 of the Western Kalahari region which lies south of the Orange River. 

 In the present state of our knowledge there seems to be no valid 

 objection to this course, since the Kalahari region, as this term is 

 usually understood by botanists, 



" is yet so imperfectly explored as to its physical divisions, 

 its aspect, its climate, and the systematic constituents of its 

 vegetation, that it will hereafter almost certainly 



require to be divided into several regions, or at least to be 

 subdivided into provinces." * 

 Some comment on the separation of Great Namaqualand from 

 Little Namaqualand is also desirable. Such knowledge as we possess 

 of the vegetation of Great Namaqualand has very largely been 

 acquired within recent years, and its effect upon the determination of 

 the botanical relationship with Little Namaqualand to the south, and 

 with other regions to the east and north of it, is not yet fully apparent. 

 Great and Little Namaqualand are separated by the lower course of 

 the Orange River, which is certainly not a phytogeographical dividing 

 line. Similarly, the northern boundary of Great Namaqualand, the 

 Swakop River, does not indicate a line of separation between two 

 floras. The line which separates it from the Kalahari to the east will 

 probably be found to coincide more or less closely with the western 

 edge of the Grass and Acacia associations which are so characteristic 

 of the Western Kalahari. Botanically, the southern part of Great 

 Namaqualand is the northern continuation of Little Namaqualand. 

 It is quite probable that the northern frontier of this great region is 

 laid down by the succulents — particularly the genera Mesembryan- 

 themum, Euphorbia, and Crassula — -which are relatively abundant 

 throughout Little Namaqualand and the southern part of Great 

 Namaqualand, as far north as a longitudinal line situated between 

 Angra Pequena and Walfisch Bay ; northwards of this line succulents 

 cease to be a dominating element in the vegetation. 



Of the Great Namaqualand localities f named in the following list, 



* Holus, loc. cit., 229, 230. 



t See map in Pearson, Journ. li. Geogr. Soc, 1910; reprinted in S. A. Mus., 

 vol. ix., part 1. 



